1. Technical Field
The present invention relates to an element that can detect a physical quantity using a vibrating reed.
2. Related Art
In related art, as a physical quantity detection element, Patent Document 1 (JP-A-2007-108053) has disclosed a vibrating reed (a vibrator in the document) including a base part, support parts respectively extending from the base part in opposite directions to each other along an X-axis direction, drive arms (drive vibrating arms) respectively extending in opposite directions to each other along a Y-axis direction at respective ends of the support parts, Y-axis detection vibrating arms respectively extending from the base part in opposite directions to each other along the Y-axis direction, and Z-axis detection vibrating arms respectively extending from the base part in opposite directions to each other along the Y-axis direction. According to the vibrating reed, parasitic oscillations of the Y-axis detection vibrating arms due to a rotation angular velocity around the Z-axis may be suppressed and an error of a measurement value of the rotation angular velocity may be reduced.
Further, there has been a vibrating reed (inertia sensor element in the document) disclosed in Patent Document 2 (JP-A-2006-267094), for example. The vibrating reed has a simple configuration in which vibration units with plural leg parts are provided, and the vibration units respectively extend from a base part in opposite directions to each other along a first direction and further respectively extend from the base part in opposite directions to each other along a second direction orthogonal to the first direction. Regarding the vibration units along the first direction, an excitation electrode is provided on one of the units and a detection electrode is provided on the other for detection of the rotation angular velocity (physical quantity) around the first direction. Similarly, the vibration units along the second direction can detect the rotation angular velocity around the second direction.
However, in Patent Document 1, the vibrating reed has the configuration in which the drive arms or leg parts extending along the Y-axis vibrate in the X-axis direction, and may perform only rotation detection around the Z-axis or rotation detection around the Y-axis, but may not perform rotation detection around the X-axis. The same is true in Patent Document 2. Further, these vibrating reeds have configurations in which the drive arms or the vibration units having the excitation electrodes individually extend from the base part, and thus, the connectivity of the respective vibration modes is weak and, for excitation of both vibrations with one oscillator circuit, fine adjustment for bringing their natural frequencies extremely closer is necessary. As measures therefor, a vibrating reed excited by two oscillator circuits is conceivable, however, according to this configuration, there has been a problem that the area of the circuit configuration part becomes larger, and downsizing becomes difficult and the cost increases.